1. Field of the Invention
The present invention relates to roll forming tools for crimping an edge trim or seal onto a flange of a motor vehicle, and more particularly, to a contact surface for a crimping roller in the roll forming tool, wherein the contact surface provides the necessary friction between the roll forming tool and the edge trim or seal, while minimizing surface damage to the edge trim or seal during installation (crimping) operations.
2. Description of the Related Art
The fitting of flange mounted automotive weatherstrips encounters a number of traditional problems resulting from manufacturing tolerances in both the weatherstrip and the vehicle.
Traditional flange mounted weatherstrips include a U-shaped profile having an embedded metallic reinforcing member, wherein the U-shaped profile is presented to the flange with the legs of the U-shaped profile in a parallel orientation. An inside surface of the U-shaped profile typically included retaining fingers that project into the channel. The U-shaped profile is operably engaged with a flange by urging the U-shaped profile against the flange to seat the closed end of the U-shaped profile against the terminal end of the flange, and the retaining fingers contact the flange and resist removal.
Typically, the flange of the vehicle to which the weatherstrip is fitted usually has a predetermined thickness, or number of sheet metal layers. However, the flange often has more or less layers of sheet metal, and thus varies from the predetermined thickness. If the weatherstrip is formed to accommodate the predetermined thickness, the weatherstrip may be too wide for a flange of fewer metal layers, yet too narrow for a flange of more metal layers. As a result, the weatherstrip may not grip satisfactorily where the flange is of fewer layers and conversely, if the flange is of excess layers, the weatherstrip may be extremely difficult to install.
These problems have been recently addressed by modifying the traditional flange-gripping portion of the weatherstrip. Specifically, the traditional U-shaped cross section of the gripping portion on the weatherstrip is formed in a splayed configuration. That is, the legs of the profile are not presented to the flange in a parallel orientation, but rather a spread configuration. The spread, or splayed, configuration allows the flange gripping portion of the weatherstrip to be initially presented to the flange with a reduced insertion force.
To operatively engage the splayed flange gripping portion, a roll forming tool is employed to deform the internal reinforcement member, such as the metal carrier, so as to engage and be retained upon the flange of the vehicle.
The roll forming tool incorporates a pair of crimping rollers rotatable in opposite directions about spaced axes, which may be parallel to one another or alternatively can be adjustable relative to one another. At least one of the rollers is rotated by any of a variety of motors, including pneumatic or electric, in conjunction with corresponding gearing between a drive shaft and the roller.
In use, the roll-forming tool is applied to the splayed flange gripping portion, and when the rollers are rotating, the rollers drive themselves onto the flange-gripping portion of the seal and by virtue of the parallel or generally parallel relationship of the rolling surfaces between the rollers will cause the flange gripping portion to be crimped into a clamping engagement on the flange. The crimping of the splayed U-shaped flange-gripping portion deforms the internal carrier and thus retains the weatherstrip relative to the flange.
However, it has been found that while the splayed flange-gripping construction offers significant advantages and in the accommodation of varying flange thickness, there is a significant tendency of the rollers to embed into the surface of the seal (upon excessive flange thickness) or spin relative to the seal without corresponding movement along the length of the seal, thereby marring the surface of the strip. Such marring, if on the edge trim portion can reduce the esthetic appeal, and if upon the sealing portion, can damage the seal to reduce its effective sealing capacity.
Therefore, the need exists for a contact surface of a crimping roller, or structure, that can reduce damage to the seal being installed. The need also exists for a contact surface to assist in accommodating a variety of flange thickness encountered by the roll forming tool.